The sum of $2$ consecutive integers is $87$. What is the first number in this sequence?
Answer: Call the first number in the sequence $x$ The next integer in the sequence is $x + 1$ The sum of the $2$ consecutive integers is: $x+ (x + 1) = 87$ $2x + 1= 87$ $2x = 86$ $x = 43$ Thus, the first number is $43$.